So...I thought I'd update a little before I went to bed. I got bored and decided to do a little testing.
GT was very kind in sending me a stripped upper receiver and stripped toggle train; that is to say --no striker,
--no extractor,
--no ejector,
--no sear bar,
--no sear bar spring,
--no barrel
Just the:
--bolt block
--front toggle
--rear toggle link
--"S" link
His works smoothly and with no resistance at all. Bolt block slides in and out of the forks with virtually zero resistance. I already have an idea of my problem, as my bolt block has significant resistance compared to his just going into the grooves in the forks.
Test 1: Replaced my upper with his upper as a complete unit. I removed my sear bar, sear bar spring and extractor to make things match. Problem is gone. Toggle pulls back with zero issues and goes home every time. No hang ups at all.
Test 2: my upper and his toggle train with "S" link. Bolt block has significant resistance going into the forks and at least twice got really tight when in full battery. Problem has returned and requires slightly more force to pull back the toggle and just a slightly harder tap to close into battery.
Test 3: His upper and my toggle train and "S" link. My bolts slips very easily into his upper. Virtually no resistance, just as his toggle does in his upper. But still, the problem has returned. Toggle sticks open when pulled completely back, but takes less "push" by my thumb to close the bolt and go into battery.
As I do this, I'm beginning to suspect that my original premise of a number of things coming together are causing the issue. I'm going to try and post some pix later, but there is a wear in places that indicate possible binding around the "shoulders" of the frame and on the bottom of one side of the fork rail. I'm also beginning to suspect that the shoulders of the frame behind the toggle have possibly been bent inward a bit owing to some strange wear patterns on the toggle train at the rear axle pin. Also, the middle axle pin, connecting the front and rear toggle parts at the top protrudes a bit and seems to bind up a little at the right side of the frame.
I'm going to get some machinist's dye and coat all of the internal metal parts and see where it rubs off. I'm going to test a hypothesis:
I think the forks on mine are torqued a bit, as a few others have surmised, during the rebarreling process long ago and it has just gotten bad enough now. The fact is that the test receiver easily accepts both bolts, and mine resists both of them.
I am simply not sure, but that's where I am and it's time for bed. Any insights with the new info would be appreciated.
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